Rule die having a powdered metal body



May 10, 1966 Filed April 6, 1964 B. W. SMITH RULE DIE HAVING A POWDERED METAL BODY 2 Sheets-Sheet l FIG. 1

FIG.6

Fl G. 4

INVENTOR.

BRUCE W. SMITH .4 82 :SR 2 3 as 3 94 92 /||2 no I22 ll8 I20 May 10, 1.966 B. w. SMITH 3,250,163

RULE DIE HAVING A POWDERED METAL BODY Filed April 6, 1964 2 Sheets-Sheet 2 FIG. 2 4o FIG.5

INVENTOR.

BRUCE W. SMITH BY Z Agent 3,250,163 RULE DIE HAVING A POWDERED METAL BODY Bruce W. Smith, Pacoima, Calih, assignor to Lockheed Aircraft Corporation, Burbank, Calif.

Filed Apr. 6, 1964, Ser. No. 357,600 7 Claims. (Cl. 83l39) This invention pertains to new and improved dies and die sets of the so-called rule type. This invention also pertains to new and improved methods of producing such dies and die sets.

At the present time it is normally considered that socalled rule dies are advantageous for use in many different types of operations because of their cost, effectiveness and longevity. In different industries the terms die and die sets are frequently used with respect to socalled rule type dies in a somewhat confusing manner. Thus, in metal working fields the term die is frequently utilized to designate an element having an opening formed therein, and such an element is utilized with a punch which fits within the opening. If the perimeter of the punch is surrounded by a steel rule like element the punch and die are normally referred as a rule type die set in these fields. In such a die set the opening in the die part may be surrounded by such a rule like strip, and various auxiliary elements or parts can be employed.

United States Patent C In other fields such as the paper industry a rule type die is considered to consist essentially of a steel rule like strip mounted on a support. v

Such a rule type die set or die is normally formed by bending a relatively hard strip of metal or rule such as steel to a desired shape, and then mounting the strip of metal upon a block of wood cut to a corresponding shape. This procedure is considered to be unnecessarily time consuming and expensive, particularly when it is followed in the manufacture of die or die set having an intricate shape. A number of efforts have been made to provide other methods for the manufacture of so-called rule type dies. As an example of this, it has been suggested to cast with respect to a rule having a desired shape a sup-,

port out of any one of a number of various different materials. It is considered that dies resulting from this generalized procedure are relatively undesirable because of factors such as die-life and the like.

vention is to provide rule type dies and die sets in which desired dimensions such as clearance between a metal 1 working die and punch can be'achi'eved without difficulty.

A further object of the present invention is to provide "dies and die sets as herein indicated which are relatively inexpensive and which are capable of being used for pro longed periods without difiiculty.

An object of this invention is also to provide new and improved methods for producing so-called rule type dies and diesets. A related object of this invention is to provide methods of this purpose which are relatively inexpensive to carry out, which may be practiced with a minimum amount of difficulty and which produce'satisfactory dies and die sets capable of being handled without break- V age and capable of being used over prolonged periods.

These and various other objects of this invention as well as many specific advantages of it will be more apparent from a detailed consideration of the remainder of this specification, the appended claims and the accompanying drawings in which:

FIGURE 1 is an exploded view showing various parts of a die set of this invention in perspective;

3,250,163 Patented May 10, 1966 FIGURE 2 is a cross-sectional view of the die set shown in FIGURE 1 with the parts of this die set in an assembled position;

FIGURE 3 is a cross-sectional view similar to FIG- URE 2 of a modified die set of this invention;

FIGURE 4 is across-sectional view similar to FIG- URE 2 of a die of this invention; and

FIGURE 5 is a cross-sectional view showing a step in the manufacture of the die shown in FIGURE 4.

Those skilled in the art of the manufacture and design of rule type dies and die sets will realize from a consideration of the drawings that these drawings are primarily intended so as to illustrate for explanatory purposes the principles of this invention. For this reason the accompanying drawings are not to be considered as limiting the scope of the present invention. The essential features of the present invention are considered to be defined or summarized by the appended claims forming a part of the present disclosure.

In order to facilitate an understanding of this invention it can be indicated in a summary manner that it concerns dies or die sets in which rule type cutting, shearing or In accordance with rule type die element or part and is then compacted with respect to this part and then both the compacted body and the rule type element together are treated so as to bond the metal powder into a metallic, rigid assembly.

The invention is best more fully explained with r'eference to drawings. In FIGURES 1 and 2 there is shown a rule type die set 10 of the present invention which consists of a die element 12, a punch element 14, a stripper plate 16 and a knockout plate 18. The die element 12 includes a rigid unitary powdered meta body 20 having an internal opening 22 formed therein. This opening 22 is bounded by a metal strip or rule 24 as a steel rule, all parts of which are parallel. A splice plate 26 of the same material as the rule 24 is preferably welded to the exterior'of this rule so as to hold its ends 28 with respect to one another. The rule 24 and the plate 26 are bonded to the body 20 in the die element 12'as hereinafter described.

The punch element 14 includes a punch plate 30 from which there projects a punch core 32. Both the plate 30 and the core 32 are formed of the same material as the body 20. This core 32 is surrounded by a rule 34 corresponding to rule 24. The rule 34 is welded to a plate 36 which is used to secure its (the rule 34) ends 38 to one another. '.The plate 36 thus corresponds to and is of the same character as the plate 26 previous-ly described. The rule 34 is formed so as to have a parallel sided exterior which is capable of fitting closely within the interior of the opening 22 along the rule 24. The rule 34 extends a short distance into the punch plate 30 and is bonded to both thispunch plate and the punch core 32 as hereinafter indicated.

The stripper plate 16'formin g a part of the die set 10 is of a flat configuration and is provided a centrally located opening 40 capable of fitting around the rule 34- on the punch element 14. This stripper plate 16 is preferably of a thickness which is less than the distance the rule 34 projects from the punch plate 30 so as to be capable of being located as shown in FIGURE 2 between the punch element .14 and the die element 12 when the punch core 32 is positioned within the opening 22. The knockout plate 18 employed with the die set 10 is of a disc-like shape, and is capable of being inserted through the opening 22 in the die element 12..

The complete die set 10 can be manufactured by first creating the rules 24 and 34 to a desired shape in accordance with conventional practice. The surfaces 41 of the rules 24 and 34 which are located opposite one another are then preferably coated with a release agent (not numbered on the drawings) such as titanium dioxide. This or various equivalent oxides can be secured in place through the use of a conventional clear lacquer such as a lacquer consisting of nitrocellulose dissolved in a suitable solvent. Such agents prevent bonding during subsequent sintering.

At the present time it is preferred to utilize finely divided iron or steel powder entirely in forming a die set such as the set 10 indicated. Such powder is of the type commonly used in the so-called powder metal field and is described in detail in a great number of technical publications. This type of material is preferred because of its availability, the fact that it can be easily utilized in the process and because of the strength of a body or plate produced from it. If desired however, various other powder metal type elements or alloys can be utilized.

The compaction step employed should, of course, utilize a pressure which is sufiiciently great so that the various quantities of powder metal indicated are rendered sufiiciently strong to withstand handling prior to sintering as a result of this step. In general it is preferred to utilize pressures which will eliminate as many of the voids within each of the bodies indicated as reasonably possible. With the use of powdered iron as indicated in the preceding pressures of from 30 to 70 tons per square inch have been found to give satisfactory results.

With this same type of material the sintering operation used in completing the die set 10 is preferably carried out in accordance with standard metallurgical practice as a temperature of from 1900 F. to 2250 F. in an inert or reducing atmosphere. Such a sintering step is, of course, carried on for a sufiiciently long period so as to develop as much strength in a powdered metal body as is reasonably possible, and after it is finished the body is, of course, cooled to room temperature under conventional conditions in the powdered metal art. These generalized conditions apply if other po wdered metals than powdered iron are used with this invention. A

The die set 70 differs from the die set by omitting the knockout plate 18 previously described. It includes a conventional metal such as steel die plate 72. This die plate 72 carries a conventional piece punch 74 formed out of rigid metal. The punch 74 extends from the die plate 72 into the interior of the opening 22'. The

die plate 72 is secured to the body 20' of the die element 12 as hereinafter described. The punch plate 30' and the punch core 32 are formed so as to include an opening 76 into which the pierce punch 74 closely fits In FIGURE 8 of the drawing there is shown a die 110 of the rule type such as is employed in paper and other industries in cutting cardboard or various sheet materials having somewhat analogous physical characteristics. This die 11! consists of powdered metal die base 112 which is bonded to a die type rule 114 of steel or other material. This die 114 extends from the surface 116 of the base 112. If desired the projecting end of it may be provided with a beveled cutting surface 118. To the surface 116 there is bonded a conventional resilient rubber polyurethane or similar resilient layer 120 serving as a stripper element. This layer 112 is bonded in place by conventional adhesive (not shown), it is provided with openings 122 in the nature of slits which accommodate portions of the rule 114 extending from the base 112.

During the manufacture of the die 110 the rule 114 is inserted within a mold 124 lined with sheets 125 of parting material as shown in FIGURE 9 of the drawings. This rule 114 is then secured in place by casting an incompressible material capable of being easily removed into .a layer 126 corresponding approximately in depth to the 4 desired thickness of the layer 120. Various common waxes such as beeswax can be used in creating the layer 126; various other comon commercial casting preparations capable of being easily broken or removed by melting or by being placed in solution can be used in order to form the layer 126. After the layer 126 becomes hard a quantity 128 of powder metal is located upon it as shown.

After these operations the quantity 128 is compacted as previously described, and then is removed from the mold 124. At this point the layer 126 may be removed in any manner appropriate to the composition of this layer; it it is of a volatile character capable of being volatilized at an elevated temperature it may be left in place. Next the structure removed from the mold. 124 is sintered as described in the preceding. After such sintering the complete die may befinished by coating the surface 116 with an adhesive and pressing the layer 120 into it. During such pressing, the openings 122 will be automatically created.

From a detailed consideration of this specification those skilled in the art of the manufacture and design of rule type dies and die sets will realize that dies and die sets as herein described can be produced relatively inexpensively and that these die sets are capable of being employed for prolonged periods without difficulty. They will also realize that the methods herein described are relatively inexpensive to carry out and that they may be practiced with a minimum of difliculty.

I claim:

1. A die set including:

(a) die element and a punch element;

(b) said die element comprising:

(c) a powdered metal unitary body having a centrally located opening formed therein;

(d) said punch element comprising:

(e) a powdered metal punch plate having an integral punch core extending therefrom and 1 (f) a die rule extending into said punch plate and surrounding said core;

(g) said rule being bonded to said punch plate and said core;

(h) said rule fitting closely within the interior of said opening in said body.

2. A die setincluding:

(a) a die element and punch element;

(b) said die element comprising:

(c) a powdered metal body having an opening formed therein;

(d) a die type die rule bounding the interior of said opening, said die rule being bonded to said body;

(e) said punch element comprising:

(f) a rigid unitary powdered metal punch plate having an extending punch core;

(g) a die type punch rule surrounding the periphery of said core and extending into the interior of said punch plate;

(h) said punch rule being bonded to said core and said punch plate;

(i) said punch rule being capable of fitting closely within said die rule.

3. A die set as defined in claim 2 including a stripper plate having an opening formed therein capable of being located between said body and said punch plate with said punch core and said punch rule extending through the opening in said stripper plate.

4. A die set including:

(a) a die element, a punch element and a knock-out plate;

(b) said die element comprising:

(c) a rigid, unitary powdered metal body having an opening formed therein;

(d) a die type die rule bounding the interior of saidopening; (e) said die rule being bonded to said body; (f) said punch element comprising:

(g) a rigid, unitary powdered metal punch plate having an extending punch core;

(h) a die type punch rule surrounding the periphery of said core and extending into the interior of said punch plate;

(i) said punch rule being bonded to saidcore and said punch plate; I

(j) said punch rule capable of fitting closely Within said die rule;

(k) said knock-out plate being capable of fitting with in said opening.

5. A die set as defined in claim 4 including a stripper plate having an opening formed therein, said stripper plate being capable of being located between said body and said punch plate with said punch core and said punch rule extending through the opening in said stripper plate.

6. A die set including:

(a) a die element and a punch element;

(b) said die element comprising:

(c) a die plate;

(d) a punch mounted on said die plate so as to extend from one side thereof;

(e) a powdered metal die body having an opening formed therein;

(f) located on said side of said die plate so as to extend therefrom with said opening being located around said punch;

(g) a die type die rule located on said die plate so as to bound the interior of said opening;

(b) said die body being bonded to said die plate and said die rule;

(i) said punch element comprising:

(j) a punch plate having a punch core, said punch plate and said punch core being integral with one another and being of powdered metal;

(k) a die type punch rule extending around the periphery of said core and into the interior of said punch plate;

(I) said punch rule being capable of fitting closely within said die rule;

(In) said punch rule being bonded to said punch plate and said core;

(n) a hole formed in said core and said punch plate for receiving said punch when said core is located within said opening in said die element.

7. A die set as defined in claim 6 including a stripper plate having an opening formed therein, said stripper plate being capable of being located between said body and said punch plate with said punch core and said punch rule extending through the opening in said stripper plate.

References Cited by the Examiner UNITED STATES PATENTS 1,701,545 2/ 1929 Show 76-107 2,195,819 4/1940 Kurtzeborn 83-139 X 2,8 18,924 -1/1958 Lang 83-685 2,821,871 2/1958 Sarno t 76-107 2,885,913 5/1959 Lescallette 83-685 2,893,489 7/1959 Thompson 83-685 3,046,815 7/1962 Moe 76-107 3,046,816 7/1962 Morin 76-107 3,048,069 8/1962 Berlin et a1 83-685 X 3,094,886 6/1963 Goerz 76-107 3,154,664 1 0/1964 Zeder 83-685 X 3,166,968 1/1965 Krouskop 83-685 X FOREIGN PATENTS 1,000,077 10/ 19511 France.

r WILLIAM W. DY ER, IR., Primary Examiner. 0 J. M. MEISTER, Assistant Examiner. 

1. A DIE SET INCLUDING: (A) DIE ELEMENT AND A PUNCH ELEMENT; (B) SAID DIE ELEMENT COMPRISING: (C) A POWDERED METAL UNITARY BODY HAVING A CENTRALLY LOCATED OPENING FORMED THEREIN; (D) SAID PUNCH ELEMENT COMPRISING: (E) A "POWDERED METAL" PUNCH PLATE HAVING AN INTEGRAL PUNCH CORE EXTENDING THEREFROM AND (F) A DIE RULE EXTENDING INTO SAID PUNCH PLATE AND SURROUNDING SAID CORE; (G) SAID RULE BEING BONDED TO SAID PUNCH PLATE AND SAID CORE; (H) SAID RULE FITTING CLOSELY WITHIN THE INTERIOR OF SAID OPENING IN SAID BODY. 